#include <stdio.h>

int main(void)

{
	int num;

	printf("请输入一个整数:");
	scanf("%d",&num);

	switch(num){
		case 1: puts("A");puts("B"); break;
		case 2: puts("C");
		case 5: puts("D");break;
		case 6:
		case 7: puts("E");break;
		default:puts("F");break;
	}	

	return (0);
}
